638-49-3Relevant articles and documents
Acidic ionic liquid based UiO-67 type MOFs: A stable and efficient heterogeneous catalyst for esterification
Xu, Zichen,Zhao, Guoying,Ullah, Latif,Wang, Meng,Wang, Aoyun,Zhang, Yanqiang,Zhang, Suojiang
, p. 10009 - 10016 (2018/03/23)
A facile strategy for the synthesis of acidic ionic liquid based UiO-67 type MOFs was developed in this study. Br?nsted acids (H2SO4, CF3SO3H and hifpOSO3H (hexafluoroisopropyl sulfuric acid)) were introduced into UiO-67-bpy (bpy = 2,2′-bipyridine-5,5′-dicarboxylic acid) frameworks by reacting with bipyridyl nitrogen to introduce the properties of an acidic ionic liquid into the frameworks. The prepared catalysts, denoted as UiO-67-HSO4, UiO-67-CF3SO3 and UiO-67-hifpOSO3, were characterized by XRD, SEM, FT-IR, EA, TGA and N2 adsorption-desorption studies. The relatively high surface area was still maintained and acidic active groups were uniformly dispersed in the frameworks. The catalytic performance of UiO-67-HSO4, UiO-67-CF3SO3 and UiO-67-hifpOSO3 was evaluated by the esterification of acetic acid with isooctyl alcohol. The prepared catalysts showed good catalytic activities in the esterification, of which UiO-67-CF3SO3 gave the maximum isooctyl alcohol conversion of 98.6% under optimized conditions. The catalyst could be reused five times without a significant decrease in the conversion of isooctyl alcohol, and almost no active species were leached, indicating the excellent stability and reusability of the catalyst. Our study provides one effective way to synthesize heterogeneous acidic ionic liquid catalysts consisting of isolated, well defined acidic groups that will probably attract interest in acid catalyst chemistry.
Alkyl Formate Ester Synthesis by a Fungal Baeyer–Villiger Monooxygenase
Ferroni, Felix Martin,Tolmie, Carmien,Smit, Martha Sophia,Opperman, Diederik Johannes
, p. 515 - 517 (2017/03/22)
We investigated Baeyer–Villiger monooxygenase (BVMO)-mediated synthesis of alkyl formate esters, which are important flavor and fragrance products. A recombinant fungal BVMO from Aspergillus flavus was found to transform a selection of aliphatic aldehydes into alkyl formates with high regioselectivity. Near complete conversion of 10 mm octanal was achieved within 8 h with a regiomeric excess of ～80 %. Substrate concentration was found to affect specific activity and regioselectivity of the BVMO, as well as the rate of product autohydrolysis to the primary alcohol. More than 80 % conversion of 50 mm octanal was reached after 72 h (TTN nearly 20 000). Biotransformation on a 200 mL scale under unoptimized conditions gave a space-time yield (STY) of 4.2 g L?1 d?1 (3.4 g L?1 d?1 extracted product).
MONOMER, POLYMER, RESIST COMPOSITION, AND PATTERNING PROCESS
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, (2014/03/21)
A polymer comprising recurring units derived from a (meth)acrylate monomer of tertiary ester type having branched alkyl on alicycle is used to form a resist composition. When subjected to exposure, PEB and organic solvent development, the resist composition is improved in dissolution contrast.
Hydroxide-promoted selective C(α)-C(β) bond activation of aliphatic ethers by rhodium(III) porphyrins
Lee, Siu Yin,Lai, Tsz Ho,Hui, Ying Ying,Chan, Kin Shing
, p. 88 - 93 (2014/05/20)
The selective aliphatic C(α)-C(β) bond activation (CCA) of ethers by rhodium(III) porphyrin halides in the presence of KOH was achieved to give Rh-C(β) alkyls up to 88% yield. The addition of H2O and a phase transfer agent Ph4PBr improved the homogeneity of the reaction mixture and significantly brought down the reaction temperature to 60 °C. At this mild temperature, the C(α) co-product was oxidized to the corresponding esters in up to 89% yield. KOH promotes the bond activation by transferring the hydroxyl group to rhodium porphyrin to generate the key intermediate RhIII(ttp)OH (ttp = 5,10,15,20-tetratolylporphyrinate dianion).
Nickel-catalyzed hydrosilylation of CO2 in the Presence of Et3B for the synthesis of formic acid and related formates
Gonzalez-Sebastian, Lucero,Flores-Alamo, Marcos,Garcia, Juventino J.
, p. 7186 - 7194 (2014/01/06)
The reaction of CO2 with Et3SiH catalyzed by the nickel complex [(dippe)Ni(μ-H)]2 (1) afforded the reduction products Et3SiOCH2OSiEt3 (12%), Et 3SiOCH3 (3%), and CO, which were characterized by standard spectroscopic methods. Part of the generated CO was found as the complex [(dippe)Ni(CO)]2 (2), which was characterized by single-crystal X-ray diffraction. When the same reaction was carried out in the presence of a Lewis acid, such as Et3B, the hydrosilylation of CO2 efficiently proceeded to give the silyl formate (Et3SiOC(O)H) in high yields (85-89%), at 80 C for 1 h. Further reactivity of the silyl formate to yield formic acid, formamides, and alkyl formates was also investigated.
2-(Sulfooxy)propane-1,2,3-tricarboxylic acid as novel and versatile catalyst for the formylation of alcohols and amines using ethyl formate under neat conditions
Ghorbani-Choghamarani, Arash,Akbaripanah, Ziba
experimental part, p. 450 - 453 (2012/06/04)
2-(Sulfooxy)propane-1,2,3-tricarboxylic acid (supported on silica gel) has been introduced as novel and green catalyst for the formylation of alcohols and amines with ethyl formate, as mild formylation agent, under neat conditions at room temperature.. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Room-temperature selective aliphatic carbon-carbon bond activation and functionalization of ethers by rhodium(II) porphyrin
Lee, Siu Yin,Lai, Tsz Ho,Choi, Kwong Shing,Chan, Kin Shing
scheme or table, p. 3691 - 3693 (2011/09/20)
Selective aliphatic carbon(α)-carbon(β) bond activation of ethers by (5,10,15,20-tetramesitylporphyrinato)rhodium(II) (Rh(tmp) (1)) was achieved at room temperature to yield corresponding rhodium porphyrin alkyls and the functionalized esters. Rh(tmp)OH was the proposed intermediate responsible for cleaving the C(α)-C(β) bond. The reaction is general for both straight- and branch-chain ethers.
Hypervalent λ3-bromane strategy for Baeyer-Villiger oxidation: Selective transformation of primary aliphatic and aromatic aldehydes to formates, which is missing in the classical Baeyer-Villiger oxidation
Ochiai, Masahito,Yoshimura, Akira,Miyamoto, Kazunori,Hayashi, Satoko,Nakanishi, Waro
supporting information; experimental part, p. 9236 - 9239 (2010/11/02)
A conceptually distinct, modern strategy for Baeyer-Villiger oxidation (BVO) was developed. Our novel method involves initial hydration of water to carbonyl compounds, followed by ligand exchange of hypervalent aryl-λ3-bromane on bromane(III) with the resulting hydrate, yielding a new type of activated Criegee intermediate. The intermediate undergoes BV rearrangement and produces an ester via facile reductive elimination of an aryl-λ3-bromanyl group, because of the hypernucleofugality. The novel strategy makes it possible to induce selectively the BV rearrangement of straight chain primary aliphatic as well as aromatic aldehydes, which is missing in the classical BVO: for instance, octanal and benzaldehyde afforded rearranged formate esters with high selectivity (>95%) under our conditions, while the attempted classical BVO produced only carboxylic acids. This firmly establishes the powerful nature of new methodology for BVO.
Dual behavior of alcohols in iodine-catalyzed esterification under solvent-free reaction conditions
Jereb, Marjan,Vra?i?, Dejan,Zupan, Marko
body text, p. 2347 - 2352 (2009/09/06)
The dual behavior phenomenon of alcohols in iodine-catalyzed esterification under solvent-free reaction conditions (SFRCs) is described; the governing factor is the stability of the carbonium ion generated from the alcohol; high concentration reaction conditions (HCRCs) or dilute solutions are much less suitable. In the case of benzylic alcohols, loss of optical activity was noted, whereas alkyl alcohols furnished a product with retention of stereochemistry.
Oxidative C-C bond cleavage of primary alcohols and vicinal diols catalyzed by H5PV2Mo10O40 by an electron transfer and oxygen transfer reaction mechanism
Khenkin, Alexander M.,Neumann, Ronny
supporting information; scheme or table, p. 14474 - 14476 (2009/02/08)
Primary alcohols such as 1-butanol were oxidized by the H5PV2Mo10O40 polyoxometalate in an atypical manner. Instead of C-H bond activation leading to the formation of butanal and butanoic acid, C-C bond cleavage took place leading to the formation of propanal and formaldehyde as initial products. The latter reacted with the excess 1-butanol present to yield butylformate and butylpropanate in additional oxidative transformations. Kinetic studies including measurement of kinetic isotope effects, labeling studies with 18O labeled H5PV2Mo10O40, and observation of a prerate determining step intermediate by 13C NMR leads to the formulation of a reaction mechanism based on electron transfer from the substrate to the polyoxometalate and oxygen transfer from the reduced polyoxometalate to the organic substrate. It was also shown that vicinal diols such as 1,2-ethanediol apparently react by a similar reaction mechanism. Copyright
